Studies will be conducted to further our understanding of the molecular mechanism of genetic recombination. Genetic analyses will examine the effects of the three different Rec pathways of E. coli and the functions of their gene products on the processes of substitution type and addition type recombination. Efforts will be made to increase the frequeny of transformation so that this technique can be used as an effective tool in studies on the ant molcules. Purification of a possible competence factor that enhances transfection will be undertaken. In addition, strains harboring mutant rec alleles will be examined for possible permeability defects.